"An advisory issued Thursday by the U.K. National Infrastructure Security Co-Ordination Centre, says the vulnerabilities affect the H.323 network protocol, a standard approved by International Telecommunications Union that helps the telephony and multimedia features on products from different vendors interoperate," reports Information Week.

"As many as 40 technology vendors may have products vulnerable to the flaws. Many are issuing security advisories and scrambling to inform their customers about the specific products that are vulnerable."

A complete list of potentially affected vendors is available at http://www.cert.org/advisories/CA-2004-01.html#vendors.